Biostatistics Decoded. A. Gouveia Oliveira

Preface

      In this second edition of Biostatistics Decoded, the style of presentation of the concepts and methods follows the same approach as in the first edition. Thus, the main features of easy mathematics requiring knowledge of little more than the basic arithmetic operations, emphasis on the explanation of the foundations of statistical concepts and on the rationale of statistical methods, and profuse illustration with working examples in a detailed step‐by‐step presentation of the statistical calculations adopted in the first edition are all present in this second edition.

      Also, in keeping with the format of the first edition, this book is written at two levels of difficulty. Readers who only wish to understand the rationale of the statistical methods may read only the plain text, without loss of continuity, while those readers who want to understand how the calculations are done should also read the text boxes.

      A great deal of new content has been included in this second edition. While the first edition was focused almost entirely on epidemiological and clinical research, in this edition several chapters covering experimental designs used in basic science research are introduced. Several important topics on study designs are also included, such as quasi‐experimental designs, pragmatic clinical trials, new designs of randomized controlled trials, and cluster randomized trials. Additions in statistical methods include not only an extensive discussion of methods based on the analysis of variance, but also an introduction to methods that are gaining great importance in data analysis, such as generalized linear models. The sections on observational studies have been expanded to better explain the various designs available and the estimates they produce. The chapter on meta‐analysis was also developed further.

      The changes to the first edition are not limited to the addition of new content. The structure of the book was reorganized according to research types, with the statistical methods used in each type of research presented immediately after the discussion of the main research designs. This chapter organization contrasts with the typical organization of most statistical textbooks, where the presentation of statistical methods is often organized first in basic concepts and applied methods, and then according to the types of variables. The organization in this book seems more relevant to practicing researchers, or professionals looking to expand their knowledge of statistical methods in a specific problem area.

This book is adequate for both introductory and advanced courses on biostatistics and research methodology, as well as for experienced biostatisticians who may find refreshing the presentation of statistical methods they may use often but not fully understand the rationale behind. The data used in the examples is either fictitious or from personal observation, and examples of computer outputs and many graphs were produced using Stata statistical software (Stata Corp., College Station, TX, USA).

      I am in debt to the faculty and staff of the Pharmacy Department of the Federal University of Rio Grande do Norte, Brazil who gave me the opportunity and motivation to develop my understanding, skills, and hands‐on experience of research designs and statistical methods applied to basic science during the last seven marvelous years at that department. Many other people have given me encouragement to pursue this endeavor, probably several of them not even being aware of the importance of their role, in particular my dear friend Ingrid Bezerra, dear Professor Ivonete Araújo, my college Rand Martins, and, most of all, my sons Miguel and Ivan to whom I dedicate this book, and, inevitably, Ana Cristina.